a) Field of the Invention
This invention relates to inspection apparatus for internally inspecting tubular members and is particularly intended for the inspection of tubular members in the field of energy exploration.
b) Description of Related Art
In U.S. Pat. No. 4,800,104 there is disclosed an inspection apparatus for determining damage such as ovality or corrosion caused to the internal surface of tubular members, especially when the tubular members are located downhole, although the U.S.A. patent also discloses apparatus for the external inspection of tubular members prior to the insertion of the members downhole.
The apparatus disclosed in the U.S.A. patent requires a body within which is located a pair of lasers which project a beam, via a number of reflectives through a window within the body to project a 360.degree. strip of radiant energy onto the interior surface of the tubular member which, upon reflection through the window, is collected and analysed to determine defects on the tubular member interior surface.
The apparatus disclosed in the aforesaid U.S.A. patent is suitable for tubular members having an internal diameter of 30 inches (76 cm) or more and because two lasers are required the power requirements are significant.
It is a first object of this invention to provide an inspection apparatus which may be used in smaller diameter tubular members and in which the power requirements of the apparatus are reduced.